Method for transmitting signal of medium access control sublayer in mobile communication system

ABSTRACT

A method for transmitting a signal of a medium access control sublayer in a mobile communication system which has mobile and base stations for providing a bearer service. A bearer service profile type is decided according to a bearer service combination type of the bearer service for the provision of the bearer service. A transport format indicator is set according to the decided bearer service profile type, and a transport format combination indicator is appended to a dedicated physical control channel. The most efficient data is transmitted on the basis of a service type and a measured radio environment result. Therefore, a data frame format most suitable to a channel environment can be produced, thereby providing the best service.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation application of prior U.S. patentapplication Ser. No. 09/406,729 filed Sep. 28, 1999 now U.S. Pat. No.7,415,040, which claims priority under 35 U.S.C. §119 to KoreanApplication No. 41482/1998 filed on Oct. 1, 1998, whose entiredisclosures are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates in general to a mobile communicationsystem, and more particularly to a method for transmitting a signal of amedium access control (referred to hereinafter as MAC) sublayer in amobile communication system.

2. Description of the Prior Art

Various methods have been proposed to transmit signals in a mobilecommunication system. One such conventional signal transmission methodmay be a data frame-type method which varies a data rate according to aservice type.

However, the above-mentioned conventional signal transmission method hasa disadvantage in that it cannot transmit efficient data because itvaries the data rate according to the service type without regardingenvironmental factors.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made in view of the aboveproblem, and it is an object of the present invention to provide amethod for transmitting a signal of a MAC sublayer in a mobilecommunication system, in which the most efficient data is transmitted onthe basis of a service type and a measured radio environment result.

In accordance with one aspect of the present invention, the above andother objects can be accomplished by a provision of a method fortransmitting a signal of a medium access control sublayer in a mobilecommunication system which has mobile and base stations for providing abearer service, comprising the first step of deciding a bearer serviceprofile type according to a bearer service combination type of thebearer service to provide the bearer service; and the second step ofsetting a transport format indicator according to the decided bearerservice profile type and appending a transport format combinationindicator to a dedicated physical control channel.

In accordance with another aspect of the present invention, there isprovided a method for transmitting a signal of a medium access controlsublayer in a mobile communication system which has mobile and basestations for providing a bearer service, comprising the first step ofallowing an application layer to decide a bearer service combinationtype of the bearer service; the second step of allowing a radio resourcecontrol layer to measure a radio environment between the mobile and basestations; the third step of allowing the radio resource control layer todecide a bearer service profile type according to the decided bearerservice combination type and the measured radio environment result andthen assign a transport format combination set; the fourth step ofallowing the medium access control sublayer to select appropriatetransport formats within the assigned transport format combination set;and the fifth step of allowing a specific layer to set attributes of adynamic part and semi-static part of the selected transport formats andappend a transport format combination indicator to a dedicated physicalcontrol channel.

In a feature of the present invention, the most efficient data istransmitted on the basis of a service type and a measured radioenvironment result. Therefore, a data frame format most suitable to achannel environment can be produced, thereby providing the best service.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will be more clearly understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIGS. 1 a and 1 b are flowcharts illustrating a method for transmittinga signal of a MAC sublayer in a mobile communication system inaccordance with the preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 a and 1 b are flowcharts illustrating a method for transmittinga signal of a MAC sublayer in a mobile communication system inaccordance with the preferred embodiment of the present invention.

A base station provides simultaneous parallel data services. Differentservices have independent bit rates, bit error rates, degrees oftransparency, throughputs, packets and circuit-switched transfer modes,respectively.

There may be about three different service types in three differentenvironments. The three different service types are generally bearerservice types with combinations of speech, circuit data and packet dataservices. The present invention includes a transport formatindicator/transport format combination indicator(referred to hereinafterrespectively as TFI/TFCI) concept related to bearer services andenvironments.

Now, a detailed description will be given of the coupling betweenTFI/TFCI values and a service profile type in communication based on thesignal transmission method of the present invention with reference toFIGS. 1 a and 1 b.

As shown in FIG. 1 a, first, an application (referred to hereinafter asAP) layer of a mobile station decides a bearer service combination typeto provide a bearer service based on a service profile type and outputsinformation regarding the decided bearer service combination type to aradio resource control (referred to hereinafter as RRC) layer.

The service profile type includes bearer service combination, bearerservice class and environment items. The TFI/TFCI values are in closeconnection with the service profile type.

The bearer service combination type includes a bearer service categorydefined by a combination of speech, circuit data and packet dataservices. The bearer service category includes any one of only thespeech service, only the circuit data service, only the packet dataservice, a combination of simultaneous speech and packet data services,a combination of simultaneous speech and circuit data services, acombination of simultaneous packet data and circuit data services and acombination of simultaneous speech, packet data and circuit dataservices.

The bearer service class type is classified into four classes A, B, Cand D according to a bit rate and a quality of service.

The class A has connection oriented and delay constrainedcharacteristics for low delay data, and is further classified into threetypes.

The first type of the class A has 8 kbps peak data rate, 20 ms delay andbit error rate (BER)<10−3 characteristics, the second type has 144 kbpspeak data rate, 50 ms delay and BER<10−6 characteristics and the thirdtype has 384 kbps peak data rate, 50 ms delay and BER<10−3characteristics.

The class B has variable bit rate, connection oriented and delayconstrained characteristics for low delay data at a variable bit rate,and is further classified into four types.

The first type of the class B has 64 kbps peak data rate, 50 ms delay,BER<10−6 and 16 kbps granuality characteristics, the second type has 144kbps peak data rate, 50 ms delay, BER<10−6 and 16 kbps granualitycharacteristics, the third type has 384 kbps peak data rate, 50 msdelay, BER<10−6 and 16 kbps granuality characteristics, and the fourthtype has 2048 kbps peak data rate, 50 ms delay, BER<10−6 and 32 kbpsgranuality characteristics.

The class C has connection oriented and delay constrainedcharacteristics for long constrained delay data, and is furtherclassified into four types.

The first type of the class C has 64 kbps peak data rate, 300 ms delay,BER<10−6 and 16 kbps granuality characteristics, the second type has 144kbps peak data rate, 300 ms delay, BER<10−6 and 16 kbps granualitycharacteristics, the third type has 384 kbps peak data rate, 300 msdelay, BER<10−6 and 16 kbps granuality characteristics, and the fourthtype has 2048 kbps peak data rate, 300 ms delay, BER<10−6 and 32 kbpsgranuality characteristics.

The class D has connectless and delay unconstrained characteristics forunconstrained delay data, and is further classified into four types.

The first type of the class D has 64 kbps peak data rate, unconstraineddelay and BER<10−8 characteristics, the second type has 144 kbps peakdata rate, unconstrained delay and BER<10−8 characteristics, the thirdtype has 384 kbps peak data rate, unconstrained delay and BER<10−8characteristics and the fourth type has 2048 kbps peak data rate,unconstrained delay and BER<10−8 characteristics.

Then, upon the information regarding the decided bearer servicecombination type from the AP layer, the RRC layer of the mobile stationperforms a measurement request/report procedure with an RRC layer of abase station. In the measurement request/report procedure, periodic,on-demand and threshold information are obtained and a radio environmentis measured on the basis of the obtained information. The RRC layer ofthe mobile station decides a bearer service profile type according tothe bearer service combination type decided by the AP layer and themeasured radio environment result and then performs a radio accessbearer set-up procedure with the RRC layer of the base station.

The measured radio environment result may generally be classified intothree models according to the obtained periodic, on-demand and thresholdinformation, or an indoor environment model, an outdoor to indoor andpedestrian environment model and a vehicular environment model. The basestation economically operates these three environment models.

In the radio access bearer set-up procedure, after deciding the bearerservice profile type, the RRC layer of the mobile station assigns atransport format combination set and transfers information of theassigned transport format combination set to a MAC sublayer and layer 1L1 of the mobile station.

Then, the MAC sublayer of the mobile station selects appropriatetransport formats within a transport format set assigned according tothe transport format combination set assigned by the RRC layer andtransfers a transport format indicator to the layer 1 L1.

The layer 1 L1 of the mobile station controls a configuration thereofaccording to the transport format combination set assigned by the RRClayer and the transport format indicator transferred by the MACsublayer.

The L1 configuration control is performed by setting attributes of adynamic part and semi-static part of the selected transport formatsaccording to the transport format combination set assigned by the RRClayer and the transport format indicator transferred by the MACsublayer.

The dynamic part attributes include a transport block size and transportblock setup size.

The semi-static part attributes include a transport time interval, atype of channel coding, outer coding such as Reed-Solomon coding, outerinterleaving, inner coding, inner interleaving and rate matching.

The outer interleaving attribute represents the depth of outerinterleaving in a radio frame and the inner interleaving attributerepresents the depth of inner interleaving in the radio frame.

Further, the layer 1 L1 of the mobile station appends a transport formatcombination indicator to a dedicated physical control channel (DPCCH)according to the transport format combination set assigned by the RRClayer and the transport format indicator transferred by the MACsublayer.

The transport format combination indicator is asymmetrically assignedbetween the mobile station and the base station.

A layer 1 L1, MAC sublayer, RRC layer and AP layer of the base stationperform the same operations as those in the mobile station,respectively, as shown in FIG. 1 b, to provide the bearer service, and adescription thereof will thus be omitted.

As apparent from the above description, according to the presentinvention, the most efficient data is transmitted on the basis of aservice type and a measured radio environment result. Therefore, thepresent invention has the effect of producing a data frame format mostsuitable to a channel environment so as to provide the best service.

Although the preferred embodiments of the present invention have beendisclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

1. A mobile station comprising: a radio resource control (RRC) layer; amedium access control (MAC) layer; and a physical (PHY) layer, whereinthe radio resource control (RRC) layer assigns a transport formatcombination set (TFCS) to the medium access control (MAC) layer, the MAClayer selects transport formats within said assigned transport formatcombination set (TFCS), and transfers transport format indicatorscorresponding to the selected transport formats to the physical (PHY)layer, the physical (PHY) layer transmits a transport format combinationindicator (TFCI) on a dedicated physical control channel (DPCCH) to abase station, and the transport format combination indicator (TFCI) isappended to the dedicated physical control channel (DPCCH) and is basedon the transport format indicators transferred by the MAC layer.
 2. Themobile station of claim 1, wherein the physical (PHY) layer further setsattributes of a dynamic part and semi-static part of the selectedtransport formats.
 3. The mobile station of claim 2, wherein theattributes of a dynamic part include a transport block size and atransport block set size.
 4. The mobile station of claim 2, wherein theattributes of the semi-static part include at least one of a transporttime interval, a type of channel coding, outer coding, and ratematching.
 5. A base station for use in a mobile communication system,comprising: a radio resource control (RRC) layer; a medium accesscontrol (MAC) layer; and a physical (PHY) layer, wherein the radioresource control (RRC) layer assigns a transport format combination set(TFCS) to the medium access control (MAC) layer, the medium accesscontrol (MAC) layer selects transport formats within the assignedtransport format combination set (TFCS) and transfers transport formatindicators corresponding to the selected transport formats to thephysical (PHY) layer, the physical (PHY) layer transmits a transportformat combination indicator (TFCI) on a dedicated physical controlchannel (DPCCH) to a receiving side, and the transport formatcombination indicator (TFCI) is appended to the dedicated physicalcontrol channel (DPCCH) and is based on the transport format indicatorstransferred by the medium access control (MAC) layer.
 6. The basestation of claim 5, wherein the selected transport formats includesattributes of a dynamic part and a semi-static part of the selectedtransport formats.
 7. The base station of claim 6, wherein theattributes of a dynamic part include a transport block size and atransport block set size.
 8. The base station of claim 6, wherein theattributes of the semi-static part include at least one of a transporttime interval, a type of channel coding, outer coding, and ratematching.